Anchored cardiac ablation catheter

ABSTRACT

An apparatus and method for performing cardiac ablations employs a catheter comprising an anchoring device and an ablating device to perform the ablations to electrically isolate the pulmonary veins and left atrium from surrounding atrial tissue. The anchor can comprise a balloon-type device, a stent-like device, a strut-like device, a spring-strut-like device, an umbrella-like device, a mushroom-like device, or other device that allows the catheter to maintain a position with respect to target tissue. The ablator can comprise a balloon ablator, an umbrella ablator, a pinwheel ablator, an umbrella ablator incorporating a cinch mechanism, a mushroom balloon ablator and a segmented balloon or pinwheel ablator. The anchor and ablator can also comprise a combination mushroom balloon anchor section and mushroom balloon ablator section. The anchor and ablator can include electrodes for measuring a conductance therebetween when in deployed position, so as to determine the effectiveness of the ablation.

RELATED APPLICATIONS

This application claims the benefit of copending U.S. Provisional PatentApplication Ser. No. 61/331,537, filed May 5, 2010, entitled ANCHOREDRING CARDIAC ABLATION CATHETER, the entire disclosure of which is hereinincorporated by reference.

FIELD OF THE INVENTION

This invention relates to cardiac ablation devices and methods for usingthe same.

BACKGROUND OF THE INVENTION

Atrial fibrillation (AF) is an arrhythmic condition of the heart inwhich the normal cardiac electrical impulses spread through the atriumin an incoherent manner, preventing the atrium from efficientlydelivering blood to the ventricle. It is estimated that over 2.2 millionAmericans and 4.5 million EU citizens suffer from atrial fibrillation.Annual costs in the U.S. related to AF are approximately $16 billion.There are approximately 300,000 new AF cases each year. Contributors toAF incidence include the aging population, and many conditions includinghypertension, cardiomyopathy, structural heart disease, diabetes, sleepapnea and obesity. Approximately 15% of stroke cases are due to clotsoriginating in blood pooling in the atria due to AF. AF is classifiedinto several types, primarily paroxysmal, and chronic, which includespersistent, and permanent with subtypes, depending on the presentationand associated morbidities. First-line treatment of AF ispharmaceutical, either through rate control, rhythm control,anticoagulation, or some combination. Due to the multiple types of AF,and the many agents and protocols used, the overall success of drugtreatment cannot be accurately stated; some estimates are that overalldrug efficacy is <40%. Additionally, some drug treatments have sideeffects that reduce quality of life or present risks.

When drug treatment is unsatisfactory, AF can be treated by destructionof the paths through which the erratic electrical impulses are spread.The destruction can be accomplished from either the epicardial or theendocardial surface, and by either mechanical means, such as the CoxMaze surgery in which tissue dissection disrupts those unwantedelectrical pathways, or by application of energy to the tissue.Energetic ablation can be performed using radio frequency (RF) energy,microwave energy, ultrasonics, or cryotherapy, among others. The goal ofablation is to create a continuous, fully transmural line of necrosedtissue, which are able to conduct electrical signals across the line,effectively creating an electrical fence. However, today's ablationtechniques are complex and have not reached high efficacy, therebylimiting their clinical utility. A particular problem is that clinicianscannot easily determine during the procedure whether the ablationproduced is likely to interrupt conduction permanently.

About 20% of ablations are epicardial; this route is chosen when othertreatments have failed, and when cardiac surgical procedures are alsoneeded, as epicardial ablation generally requires heart bypass. Theremaining 80% are endocardial, performed using a percutaneous catheterinserted into a vein, then into the right atrium, and then via atrans-septal puncture through the septum into the left atrium. The mostcommon ablation techniques attempt to create circumferential ablationsaround the ostia, the locations where the pulmonary veins (PV) enter theleft atrium. This isolates the disorganized signals arising in the veinsfrom the atrium, without inducing stenosis due to pulmonary veinablations. However, of the approximately 1 million AF patients in the USnot successfully treated with drugs, only about 100,000 are treated byablation annually. More are not treated by ablation due to itsdifficulty and the wide variation in treatment efficacy. Approximately40% are repeat ablation procedures.

Endocardial catheter ablation is currently a two to six hour procedureperformed by electrophysiologists (EPs). Much of this time is needed fora spot by spot creation of the required circumferential ablations usingthe ablation tools currently available, along with the time spent toverify conduction block, and follow-up during the procedure to insurethat conduction block has been maintained, and when not, reablatespecific locations as determined via conduction measurements. Reportedlong term success rates range from 20-70%. The efficacy decreases as AFprogresses. To achieve even these results, approximately 40% of patientsrequire repeat procedures at significant cost to the healthcare system,along with the radiation exposure from imaging and other risks to thepatient and to the clinician inherent in these procedures. Marketresearch indicates that both the variations in efficacy and the lengthyduration of the procedure are primarily due to uncertainty on the partof the clinician during the procedure as to whether the ablation lesionis continuous, complete, permanent, and transmural.

Present commercial minimally invasive catheter ablators consist ofnumerous single point ablation catheters, as well as a number of morerecent devices, including a balloon catheter utilizing a laser energysource, a balloon catheter utilizing cryothermal energy, amulti-electrode ablator, utilizing RF energy and various robotic systemsto maneuver catheters through the vascular system into the heart.

The two balloon ablators are applied in a similar manner, as they areinserted via a catheter and placed at the ostium, or intersection of thepulmonary veins with the atrial wall. Their placement limits theirapplication to only electrically isolating unwanted signals around thepulmonary veins from the rest of the heart. Electrophysiologists, whoperform the ablation procedures have also indicated that follow-up spotsstill need to be ablated, and there have been reports of injuries tosurrounding tissue such as the phrenic and vagus nerves, and stenosis ofthe veins. Since they occlude blood flow through the vein, the balloonsneed to be adequately stiff to oppose the pressure from the blood flow.This is desirable in order to maintain their position and contact withthe target tissue during the ablation cycle, otherwise they are lesslikely to achieve a continuous abaltion.

The multi-electrode array ablator, mounted on a Nitinol frame, can beused to map, ablate, and verify the ablation line by measuringconduction block, across the ablation line, around the pulmonary veinsor in other target areas. Although this device can use its Nitinol frameto more readily conform to the target surface, while using a low levelof applied force, which can provide enhanced contact to maximizeablation energy transfer, electrophysiologists have reported that thisrequires additional discrete point ablations to be performed. Thisincreases procedure time and reduces the likelihood of generating acontinuous, fully transmural ablation. To maintain contact between thearray and target tissue requires the electrophysiologist to continue toapply force during the ablation cycle, similar to point and balloonablators. Because each ablator electrode in the array resides in acontinuous ring, it may not satisfactorily conform to the targettissue's topography.

There are a number of robotic systems in development and alreadycommercialized that augment the clinician's ability to maneuver thecatheter to the selected target in the vascular system, includingchambers in the heart. One such robot system allows a magnet to direct acatheter to a target and hold it against the target. It is designed tomaneuver and hold point ablators. Point ablators take significantprocedure time and do not necessarily generate continuous lesion linesto block unwanted electrical pathways. In addition the robots are veryexpensive.

However, present methods and technology do not provide features forlocating and fixing in place the ablative element(s) that are physicallyseparate from the mechanism for performing the ablation. This lack ofseparation limits the capability of devices based on these priorinventions to accurately locate the tissue volume to be ablated withrespect to the pulmonary vein target at a location which minimizes thepossibility of pulmonary stenosis, while also adjusting the contact ofthe ablative element(s) to provide intimate and accurate contact of theablative element(s) with the atrial tissue and thereby form an ablatedvolume that fully encloses the ostium of the pulmonary vein.

In addition, the balloons and multi-electrode array are constructed andarranged to apply a continuous ablation line. These technologies arelimited because they must be in continuous contact throughout theablator-tissue contact range. They have problems maintaining thatcontact during the ablation cycle.

Also, prior systems employ primarily only point ablators to generatelesion lines beyond the pulmonary vein isolation technique, whichcreates a circumferential abvlation around the pulmonary veins. However,this is a difficult procedure, which requires a high level of skill,exposes the clinicians and patient to radiation during imaging, extendsprocedure durations and reduces efficacy.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages of the prior art byproviding an apparatus and method for use in performing endocardialablations to electrically isolate the pulmonary vein(s) from thesurrounding atrial tissue. An illustrative embodiment of the apparatusis in the form of a catheter with an external sheath, retractable tovarious positions as known to those skilled in the art. In addition, asecond embodiment provides the capability to perform linear ablationlines as well. According to various embodiments herein, the catheter isintroduced into the pulmonary vein with a Guide catheter. An option isto provide steering within the main catheter, and to operate free of aguide catheter.

The catheter, at its distal end, is assembled with an anchoring devicebeneath the sheath so that the anchor expands upon initial refraction ofthe internal sheath. When the catheter tip has been placed within apulmonary vein, and the sheath initially retracted, the anchoring deviceexpands and contacts the interior wall of the pulmonary vein, and exertsa radial force on the wall, anchoring and centering the catheter withrespect to the lumen of the pulmonary vein at that location. By alsopulling the anchoring device in a proximal direction, (towards theuser), the anchor will be too large to pull through the vein's exit intothe atrium, thereby enhancing the anchoring device. Several specificembodiments of the anchoring device are presented below.

The catheter also includes, at a separate location proximal to that ofthe anchoring device, an ablation device. After the catheter has beenanchored in the vein, an additional retraction of the external sheathallows the expansion of the ablation device. A variety of ablationdevice designs and implementations can be employed in according withvarious embodiments herein.

After deployment of the ablation device, a secondary manipulation of thecatheter can be employed to force the ablation device components intointimate contact with the atrial tissue, prior to the initiation of theablation step. Examples of actuators to carry out this illustrativesecondary manipulation of the catheter are detailed in the drawings andspecifications below.

Both the anchoring device and the ablation device can also employadditional electrical conductors, operatively connected to that cathetercontrol system, and typically provided separate from the ablationcontrol or the anchoring device. The additional conductors are placed incontact with the tissue generally remote from (away from) the ablatedtissue volume, by the expansion of the anchoring and ablation devices,respectively. The additional conductors can be used, while the anchoringand ablation devices remain in place, to assess the presence or absenceof conduction block across the volume of tissue ablated during or afterthe ablation process. This step prevents having to estimate where toplace the feedback sensors with respect to the ablation volume. The useof such conductors to assess the presence or absence of conduction blockthrough the ablated tissue volume is well known to those skilled in theart.

In order to optimize radio-frequency ablation, a bipolar circuit istypically desirable, so as to direct and focus the ablation energy in anefficient and safe manner. There are a number of options to create abipolar conduction path. A typical method includes a conductive padplaced under the patient, but according to this method the energy willbe disbursed in many directions. One alternate return circuit can beincluded on, or adjacent to the ablator, such that the return circuit isbe on the same side of the ablator with respect to the atrial wall. Thereturn circuit typically defines a greater distance from the ablatorthan the thickness of the target tissue in order to maximize thelikelihood that a full thickness ablation is achieved. Another optioncan be to place a return electrode on the epicardial (outside) surfaceof the heart. The option of placing the return electrode across from theablator, is often desirable in terms of the electrical characteristicsof the system, as the energy is significantly focused and applied in ahighly efficient manner. An optional return circuit can include anelectrode on a minimally invasive device to be inserted into and mountedon or located near (proximate to) the wall of the esophagus, adjacent tothe heart. Since this can be applied with standard minimally invasivedevices, and yields a relatively short electrical path, it can be adesirable method of applying ablation energy. Illustratively, theelectrode can reside in the lumen of the esophagus, or can be attachedto the wall of the esophagus, using an anchoring system similar to thatproposed for the anchor in the pulmonary vein.

As a further feature of the apparatus and method, during catheterablation procedures, Transesophageal Echocardiographic (TEE) Ultrasoundis often used as a guidance tool for placing the ablator. The TEEinstrument can also include an electrode for the return ablation energycircuit as described above. A minimally invasive device inserted intothe esophagus can also contain one or more magnets, in whichopposite-pole magnets can be included in the ablator device. Thus theTEE device can include magnets to enhance, or provide, the primeanchoring technique for holding the ablator against the target.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention description below refers to the accompanying drawings, ofwhich:

FIG. 1A is a side view of a point ablator including a balloon anchorwith discrete point ablator catheter, in accordance with an illustrativeembodiment;

FIG. 1B is a front view of the compass ablator according to theillustrative embodiment;

FIG. 2A is a cross-sectional view of the catheter and associated sheathfor a catheter, having two steering cables, and optional guide catheterlumen, according to the illustrative embodiments;

FIG. 2B is a cross-sectional view as taken through the catheter andassociated sheath for a catheter, having four steering cables, andoptional guide catheter lumen, according to the illustrativeembodiments;

FIG. 3A is a side view of an anchor umbrella and ablator umbrella shownin the stored position, according to the illustrative embodiments;

FIG. 3B is a detailed side view of the strut details, according to theillustrative embodiments;

FIG. 4A is a side view of the anchor umbrella and ablator umbrella,shown in the deployed position, according to the illustrativeembodiments;

FIG. 4B is a front view of the anchor umbrella and the ablator umbrella,shown in the deployed position, according to the illustrativeembodiments;

FIG. 5A is a side view of the anchor umbrella and an ablator pinwheel,shown in the deployed position, according to an illustrative embodiment;

FIG. 5B is a front view of the anchor umbrella and the ablator pinwheel,shown in the deployed position, according to the illustrativeembodiments;

FIG. 6A is a side view of a mushroom anchor and an ablator umbrella,shown in the stored position, according to an illustrative embodiment;

FIG. 6B is a front view of the mushroom anchor and the ablator umbrella,shown in the stored position, according to the illustrative embodiments;

FIG. 6C is a side view of the mushroom anchor and the ablator umbrella,shown in the deployed position, according to the illustrativeembodiments;

FIG. 6D is a front view of the mushroom anchor and the ablator umbrella,shown in the deployed position, according to the illustrativeembodiments;

FIG. 7A is a side view of a balloon anchor and a balloon ablator, shownin the deployed position, according to an illustrative embodiment;

FIG. 7B is a front view of the balloon anchor and the balloon ablator,shown in the deployed position, according to the illustrativeembodiments;

FIG. 8 is a side view of an umbrella anchor and an umbrella ablatorcinch mechanism operatively connected to a helix drive, according to anillustrative embodiment;

FIG. 9A is a side view of a combination mushroom and balloon anchorhaving ribs and an ablator balloon, according to an illustrativeembodiment;

FIG. 9B is a front view of the ablator balloon according to theillustrative embodiment;

FIG. 10A is a side view of a combination mushroom and balloon anchorhaving non-occluding ribs and a balloon ablator, according to anillustrative embodiment;

FIG. 10B is a front view of a segmented ablator balloon, according tothe illustrative embodiment;

FIG. 11A is a side view of a separated mushroom-balloon anchor havingnon-occluding ribs and an ablator balloon, according to an illustrativeembodiment;

FIG. 11B is a detailed cross-sectional view as taken through the line11-11 of FIG. 11A, according to the illustrative embodiments;

FIG. 11C is a front view of the ablator balloon, according to theillustrative embodiments;

FIG. 12A is a side view of an umbrella anchor and an annular balloonablator, according to an illustrative embodiment;

FIG. 12B is a front view of the annular balloon ablator, according tothe illustrative embodiment;

FIG. 13A is a side view of a magnet anchor as part of a transesophagealechocardiogram (TEE), according to an illustrative embodiment;

FIG. 13B is a front view of the magnet anchor as part of the TEE,according to the illustrative embodiment;

FIG. 14A is a flow chart of a procedure for performing an anchoredcardiac ablation, according to an illustrative embodiment;

FIG. 14 is a perspective view of an umbrella ablator and mushroom anchorin place in the left superior pulmonary vein, in the left atrium of apatient, according to the illustrative embodiments;

FIG. 15 is a perspective view of the resulting ablations in the leftatrium, according to the illustrative embodiments;

FIG. 16 is a perspective view of the umbrella ablator and mushroomanchor, and further performing a roofline ablation, according to anillustrative embodiment;

FIG. 17 is a perspective view of the umbrella ablator and mushroomanchor, further including a balloon support for the catheter, accordingto the illustrative embodiments; and

FIG. 18 is a schematic diagram of a system employing an anchoringcardiac ablation device in accordance with the illustrative embodiments.

DETAILED DESCRIPTION

An apparatus and method for performing cardiac ablation employs acatheter and various anchoring and ablation techniques, according toillustrative embodiments described herein. The various arrangements andtypes of apparatus components are shown in the illustrative embodimentsof FIGS. 1-18.

A. Catheter Including Balloon Anchor and Compass Ablator

Reference is now made to FIGS. 1A and 1B showing, respectively, a sideand front view of an illustrative embodiment of a cardiac ablationcatheter comprising a point or “compass” ablator and balloon anchor. Thepoint ablator is maneuvered circumferentially similar to a compass,thereby this embodiment is referred to as a compass ablator 100 includesa balloon anchor 101 at the distal tip 110 of the catheter 103. An“anchor”, as the term is used generally herein, refers to the structureassembled on a distal end of the catheter for application within thepulmonary vein. The anchor structure expands radially outwardly so as tocontact the pulmonary vein wall. The catheter as generally used hereinrefers to a catheter having an external diameter of approximately 12French (F), which can be more or less depending on the particularapplication and includes lumens and conductors as appropriate for theparticular application as described herein.

The catheter 103 includes a protective outer sheath with lumen 102.Proximal to the anchor 101 is a point ablation catheter 104 emanatingradially at an angle from the midcath 103 to contact the atrial wall 107around the pulmonary vein 106. This is the catheter that is used duringthe ablation phase. A pacing catheter 108 is disposed proximal to thepoint ablation catheter 104. The pacing catheter 108 is arranged tocontact the atrial wall tissue 107 radially outside the ablation line.By emitting an electrical signal from the pacing catheter 108, theelectrical contact on the anchor detects the pacing signal if theablation line is incomplete. The term “ablator” as used herein refersbroadly to the structure assembled proximal to the anchor and onto thecatheter, having a circumferential configuration so as to surround thetissue surrounding the pulmonary wall. The ablator can be anyappropriate shape and use any of a variety of modalities (or combinationof modalities, such as resistance heating, RF, ultrasound, etc.) toperform ablation of internal tissue. Moreover, the ablator configurationcan be constructed and arranged to define any shape that is suitable foruse in conjunction with the pulmonary vein opening, as described ingreater detail hereinbelow.

The anchor 101 provides stabilization to the ablator 100 for this andother embodiments described herein. The stabilization effect providedallows physicians and/or other clinicians to utilize a standard“off-the-shelf” point ablator while maintaining the various advantagesdescribed herein. The anchor also allows a user to have more control ofthe point ablator contact because the catheter is anchored within adesired portion of the heart and ablation can be targeted morespecifically. The anchor moreover allows for additional linear ablationlesion lines such as a roof line (shown in FIGS. 16 and 17) or otherablation techniques known to those having ordinary skill.

B. General Catheter Structure

Reference is made to FIGS. 2A and 2B showing a cross-sectional view astaken through the catheter 103 of FIG. 1 and other embodiments of thecatheter shown and described herein. FIGS. 2A and 2B show the catheter103 a, 103 b having an outer lumen 102 with an outer diameter D1 ofapproximately 0.158 inches in an illustrative embodiment. The innerdiameter D2 of the outer lumen 102 is approximately 0.128 inches and theouter diameter D3 of the catheter 103 a, 103 b is approximately 0.125inches. These measurements are for illustrative purposes to provide anexemplary embodiment and are highly variable within the scope ofordinary skill. These sizes can be used in the various embodiments asdescribed herein.

FIG. 2A shows a catheter 103 a having two steering cables according toan illustrative embodiment. The catheter 103 a includes conventionalfluid lumens 201 and provides the two depicted steering cables 202 forsteering the catheter as it is manipulated through the body/vasculatureto reach a destination. The cathether 103 a of FIG. 2A includesillustrative conductors 203 appropriately positioned to allow for theelements of the catheter to be disposed therein. A lumen to accommodatea guide catheter 204, as an option is described in greater detailherein, is also provided. The positioning of such catheter elements, andnumbers of each type of element within the catheter is highly variable,as will be readily apparent to those having ordinary skill.

FIG. 2B shows an illustrative catheter 103 b having four steeringcables. The catheter 103 b of FIG. 2B includes conventional fluid lumens201 and four steering cables 202. The conductors 203 are also providedin the catheter to provide the appropriate connectivity for electricalsignals that perform ablations. A lumen to accommodate a guide catheter204 an option for the catheter is also provided, as is described ingreater detail hereinbelow.

C. Catheter Including Umbrella Anchor and Umbrella Ablator

An embodiment employing an illustrative umbrella anchor and umbrellaablator is shown in FIGS. 3A, 3B, 4A and 4B. As shown in the side viewof FIG. 3A and the front view of FIG. 3B, the umbrella anchor 301 isshown deployed in the pulmonary vein and the umbrella ablator 302 isshown in the stored position. The umbrella anchor and umbrella ablatorin one embodiment can be opened passively by being fabricated fromshape-memory materials such as certain aluminum alloys, nitinol oranother appropriate metal, or yet other appropriatematerials/structures. In another embodiment, the anchor and/or ablatorcan be positively actuated to the deployed position, rather thanattaining this position via the spring action of a memory material. In astored position the anchor/ablator according to various embodimentsreside and are packaged within, or on, a catheter under a sheath so asto allow for passage from an entry port to the left atrium. Once locatedat the desired position, the outer sheath is withdrawn or pulledproximally (see arrow A3), to expose the umbrella ablator 302 and allowit to expand to its deployed position as shown in FIGS. 4A and 4B. Notethat although the outer sheath 102 is withdrawn (orretracted/pulled/moved) in FIG. 3A and shows the umbrella ablator 302 inthe stored position, in operation as the sheath 102 is withdrawn, itcauses the umbrella ablator 302 to expand concurrently in embodimentsconstructed from a shape memory alloy. It is shown in the storedposition with the sheath retracted for illustrative and descriptivepurposes. This embodiment provides a manual control for activation ofthe umbrella ablator. Various other embodiments, which include automatedactivation mechanisms or electric actuators for deploying the ablator,are described and shown herein.

The anchor is opened to an expansion of the pulmonary vein based on theradial force of the anchor against the pulmonary vein wall. The forcemeasurement can be achieved illustratively by one or more micro forcesensors mounted on the struts of the anchor. By way of example, one suchforce sensor can be a microstrain gauge. This form of gauge directlymeasures the radial expansion force. A second indirect optional forcemeasurement can be achieved by measuring the tensile force on the cinchcable (as shown in FIG. 8).

FIG. 3B shows a representation of a strut for an ablator. The umbrellaablator 302 is stored within the catheter 103 and consists of an arrayof struts 312 with an ablation circuit 306 on one side so it willcontact the tissue at the tissue interface. An electrically insulativematerial 305 is applied between the ablation circuit 306 and feedbackcircuit 310. The details of struts 312 can also be provided for theumbrella ablator struts that are described herein.

The umbrella anchor 201 is shown as an open-end, stent-like device. Itcan have an electrical feedback circuit (not shown) contacting thetissue. A single force sensor (not shown) can be included, for examplein the umbrella ring 313, to detect and send axial compression forcebetween the umbrella 302 and anchor 201. Alternatively, force sensorslocated on each strut, not shown, but as part of a feedback circuit canbe included to detect force at each ablator electrode.

FIGS. 4A and 4B show, respectively, side and front views of the umbrellaanchor 301 and umbrella ablator 302 in the deployed position. Ablationoccurs when power is emitted through the ablator circuit 401 to thetarget tissue, such as an atrial wall 107. A separate return circuit canbe deployed and energy can return through an electrode placed in theesophagus (not shown here, but refer to FIGS. 13A and 13B for a TEEanchoring system). A return electrode can also be included in theumbrella or can be deployed on heart tissue beyond/outside thecircumference of the ablation line. Conduction is measured across theablation lines via electrodes (not shown) that contact outside theablation ring (similar to the strut construction in FIG. 3B) and 105(inside the ablation ring). Acceptance criteria is based upon catheterdata collections and observations. If power requirements precludeablation through an entire circumferential ablator, one or more segmentscan be ablated through a device similar to the ablator pinwheelstructure 502 of FIG. 5B and other ablators as described herein. Uponcompletion of a first ablation step, the entire ablator (for exampleablator 302 of FIGS. 4A and 4B) can be rotated about the axis of theanchor in place in the pulmonary vein 106. Rotation of the ablatoroccurs such that previous ablation overlaps each subsequent ablation.Refer to FIG. 15, described hereinbelow, for a perspective view of theresulting ablations in the left atrium of a patient, in accordance withthe various illustrative embodiments herein.

The umbrella anchor 301 of FIGS. 3A, 3B, 4A and 4B, and otherembodiments described herein, desirably provides stability for theablator, and allows the umbrella ablator to be cinched down orcompressed against the posterior atrial wall around the pulmonary vein.Notably, the umbrella anchor allows blood to flow therethrough duringthe ablation phase with negligible obstruction. The umbrella ablatorfurther allows the ablator structure and in particular its conductingelectrode surface to maintain contact with the atrial wall 107 duringthe ablation phase, thereby providing a stable base for performing theablation.

D. Catheter Including Umbrella Anchor and Pinwheel Ablator

Reference is now made to FIGS. 5A and 5B showing, respectively, a sideand front view of an umbrella anchor 301 and a pinwheel ablator 501shown in the deployed position. When in the stored position, thestructure resembles the catheter structure of FIGS. 3A and 3B. Asdepicted in FIGS. 5A and 5B, each strut 502 of the pinwheel ablator 501is separate from adjacent struts 502. Each strut, as the conductorbetween the driving circuit and target tissue, has an electrode which isto be positioned in intimate contact with the target tissue. Each strut502 of the pinwheel ablator 501 also defines a compound curve 503 ofappropriate arrangement to provide the desired overall structure for,and positioning of the electrode surface against the tissue inpreparation for ablation. The struts 502 of the pinwheel 501 can beconstructed from a memory metal wire, or another appropriate material.The number of struts 502 on the pinwheel 501 is highly variable toachieve the desired circumference for ablation. The struts are alignedsufficiently close together circumferentially, in order to provideoverlapping ablation energy with respect to each adjacent electrodethereby creating a continuous ablation line. In the event that anyablation line formed by the device is not continuous, the ablator can bepulled slightly distally, rotated and reseated to create an overlappingablation segment.

The umbrella anchor 301 allows blood to flow therethrough duringablation and provides a structural surface for electrical contact for afeedback circuit. The discrete ablator struts 502 of the pinwheelablator 501 allow for each strut to have a distinct electrode to conformto the rough topography of the atrial surface 107. A micro force sensormounted on each electrode pad can insure that each electrode is insufficient contact, or that the particular electrode is not used in theablation process. In addition, impedance and/or current measurementthrough each ablation electrode can provide a significant source ofadditional feedback to determine if each electrode is in sufficientcontact to allow it to be used in the ablation. The discrete ablatorelectrodes for each ablator strut 502 are also readily stored within thecatheter when in the stored position.

E. Catheter Including Mushroom Anchor and Umbrella Ablator

Reference is now made to FIGS. 6A-6E showing an active mechanism todeploy an umbrella that incorporates a mushroom anchor 601 according toan illustrative embodiment. Other active mechanisms for umbrelladeployment can include electro-actuators, shape-memory alloy,piezoelectric or similar technology and materials. FIGS. 6A and 6B show,respectively, side and front views of the mushroom anchor in the storedposition. FIGS. 6C and 6D show, respectively, side and front views ofthe mushroom anchor and umbrella ablator in the deployed position. Asdepicted in the detail ‘E’ of FIG. 6C, the mushroom anchor includesspring struts 603 that are rigidly supported on a proximal support ring602 and a distal support ring 604. According to the illustrativeembodiment, the proximal ring 602 is fixed and the distal ring 604 ofthe mushroom anchor 601 can be moved proximally (see arrow A6) and thespring struts 603 are compressed. Alternate arrangements for fixation ofthe ring to provide compression of the struts are expressly contemplatedand should be apparent to those having ordinary skill. For example, thedistal ring can be fixed and the proximal ring can be movable, or bothrings can be movable relative to each other to provide for the desiredmovement characteristic for the struts. The spring struts 603 can have apre-set bend which are activated upon proximal movement of the distalring 604 of the mushroom anchor 601. Actuated movement in bothdirections of one or both of the rings 602 and 604 can be desirable toinsure enhanced control and proper closure of the anchor during removal,prior to reinserting the inner sheath over the anchor.

The mushroom anchor 601 allows blood to flow therethrough during theablation phase, and any time proximate thereto. The mushroom anchor issecured by rings or other appropriate structures to provide sufficientrigidity, while allowing the distal end of the anchor to be movedproximally, or the proximal end to be slid/advanced distally, therebyproviding a controlled radial expansion of the anchor against thepulmonary vein wall. Force sensors, such as microstrain gauges (notshown), located on at least one strut, and/or optionally mounted onpairs of diametrically opposing struts can be included.

H. Catheter Including Balloon Anchor and Balloon Ablator

Reference is now made to FIG. 7A showing a side view of a balloon anchorand balloon ablator according to an illustrative embodiment. As shown,the balloon anchor 701 is inserted into the pulmonary vein 106. When inthe desired position, the balloon anchor 701 is expanded until itcontacts the pulmonary vein wall 106 sufficiently to maintain itsposition within the vein as shown in FIG. 7A. The balloon ablator 702 isthen also expanded to its desired size. The balloon ablator 702 is thenadvanced distally (arrow A7) until its conduction block circuit 705(shown in FIG. 7B, as taken through line 7-7 of FIG. 7A) and ablationcircuit 706 contact the atrial wall 107. The balloon anchor 701 andballoon ablator 702 can be expanded and/or activated by pumping abio-compatible fluid (e.g. saline solution), or other safe workingmaterial into each balloon chamber as desired. Balloon pressuremeasurement can be used analogous to force measurement to relate thatpressure to anchor retaining force or ablation compression force, asknown to those having ordinary skill. The balloon ablator 702 andballoon anchor 701 can be more conformable to the patient's atrialtopography than conventional strut devices, and also provide wider loaddistribution against the adjacent tissue. Additionally, the balloons canbe readily constructed according to conventional techniques and easilystored within the catheter.

I. Catheter Including Umbrella Anchor and Umbrella Ablator

Referring now to FIG. 8, an umbrella anchor 301 and umbrella ablator 302are shown further including a cinch mechanism according to anillustrative embodiment. As shown, a cinch cable 803 is connected to theumbrella ablator ring mount (UARM) 313 and passes through a pulley 804on the anchor ring mount (ARM) 801 back to a helical drive mechanism 802on the external control device (not shown). Turning the helix drivemechanism 802 exerts tension on the cable 803, and allows the ablator302 to be compressed against the target tissue on the atrial wall 107.Other forms of mechanisms (not shown) can include a mini-helical drivewithin the catheter from which the ablator can be advanced, as commonlyapplied by those having ordinary skill. A linear slide and catch drivemechanism, although not shown, is another ablator compression mechanism,known commonly in the art as a “Quick-Grip bar” or a Clamp mechanism.The cinch mechanism of FIG. 8 allows the ablator to be moved orcompressed against the target tissue according to an illustrativeembodiment.

J. Catheter Including a Combination Mushroom Balloon Anchor and MushroomBalloomn Ablator

Reference is now made to FIGS. 9A and 9B showing, respectively, a sideand front view of a combination mushroom and balloon anchor havingnon-occluding ribs and a balloon ablator, according to an illustrativeembodiment. The mushroom balloon anchor 902 and mushroom balloon ablator901 are combined into a single structure, as shown in FIG. 9A. Once theanchor is properly set, the balloon expansion will compress its distalsurface with the ablator and conduction block circuits against theatrial wall 107. The mushroom balloon anchor 902 and combined ablator901 includes segmented sections 904 so that each section canindependently contact tissue and slide with respect to adjacentsections. Bypass holes 703 and 704 are provided which allow blood tocontinue to flow through the pulmonary vein during the combinationmushroom balloon anchor occlusion of the vein during the ablation phase.The size of the bypass holes is highly variable.

K. Catheter Including a Combination Mushroom Balloon Anchor and MushroomBalloomn Ablator Having Separated Segments

FIGS. 10A and 10B show, respectively, a side view and a front view of acombination mushroom balloon anchor 1002 and ablator 1001, according toan illustrative embodiment. As shown in FIG. 10B, the mushroom balloonablator 1001 includes separated segments 1004 that allows for eachsection to contact tissue independently. The segmented anchor balloonallows blood to flow therethrough during the ablation phase, whichlessens the occlusion effect of conventional balloon procedures. Thesegmented balloon also provides localized contact against the atrialposterior wall. Turning the ablator balloon 1001 about the axis of theanchor balloon 1002 generates a continuous circumferential ablation (asshown in FIG. 15 as ablations 1510, for example). Bypass holes 703 and704, (see for example FIG. 7A), can be included to provide bloodflowtherethrough when inflated.

L. Catheter Including a Mushroom Balloon Anchor Separated from a BalloonAnchor

Referring to FIG. 11A, a separated mushroom balloon anchor withnon-occluding ribs and mushroom balloon ablator is shown according to anillustrative embodiment. The anchor balloon 1101, as shown in greaterdetail in FIG. 11B as taken through line 11-11 of FIG. 11A, includesnon-occluding ribs, and is separated from the mushroom balloon ablator.The balloon anchor 1101 is inserted and inflated within the pulmonaryvein 106. Once sufficiently inflated to maintain position, the balloonablator 702 is inflated. The balloon ablator is then compressed againstthe atrial wall 107. Bypass holes can be included for allowing blood toflow therethrough. The separated mushroom balloon ablator allows forfull contact of the ablator with the target tissue. Also, the separatedmushroom balloon provides localized contact against the atrial posteriorwall, similar to the struts 502 in the pinwheel structure.

M. Catheter Including an Umbrella Anchor and Annular Balloon Ablator

Reference is now made to FIG. 12A showing a side view of an umbrellaanchor 301 and an annular ablator balloon 1201 having a unique annularring. The annular ring includes circuits 401 on its surface, protrudingdistally toward the atrial wall 107. The conductor circuits 401 includethe ablator circuit 1202, conduction block circuit 1203 and an optionalforce sensor circuit (not shown). In operation, the circuits 401 arecompressed against the target tissue of the atrial wall 107. Thecombination umbrella anchor with annular balloon ablator allows full andtargeted contact of the ablator with the target tissue and in the ostiumvascular system (vs) at the pulmonary vein. The contour of the annularballoon ablator includes the boss-like ring features that provide fullcontact with the target tissue.

O. Magnetic Anchor as Part of a Transesophageal Device

Reference is now made to FIGS. 13A and 13B showing, respectively, a sideand front view of a magnet anchor as part of a transesophagealechocardiogram (TEE), according to an illustrative embodiment. One ormore magnets 1302 are included in an instrument located proximate anesophagus 1301. The magnets 1302 provide sufficient force to anchor theablator return circuit 1305 in position with respect to the pulmonaryvein 106. Additional anchors can also be provided to improve the overallanchoring effect including use of a balloon anchor, umbrella anchor, orother structures as described herein. The illustrative magnetic anchors1302 provide a holding mechanism opposing the ablator. Ablator returncircuit 1305 provides a directly transmurally opposing (i.e. through thewall) return circuit, which optimizes the ablation field and therebyprovides effective ablation.

P. Medical Treatment Procedure for Cardial Ablation

Reference is made to FIG. 14A showing a flow chart of a medicaltreatment method or procedure for performing an anchored cardiacablation, according to an illustrative embodiment. At step 1401 theprocedure initiates when a catheter is inserted into the pulmonary vein.The catheter reaches the pulmonary vein by being steered into the rightatrium. A transseptal puncture is then created through the septal walldividing the two atria or upper chambers in the heart. The catheter (orguide catheter) is advanced into a pulmonary vein. Once the catheter isat the desired location, inner sheath is pulled proximally. The anchorof the catheter is expanded into the pulmonary vein at step 1402 againstthe pulmonary vein to a predetermined force as measured by a micro forcesensor. Then at step 1403, the ablator device is opened to apredetermined size and then it is moved towards a surface of the atrialwall at step 1404. The ablator compression force is then maintained atstep 1405 to achieve a predetermined contact, as measured by a microforce sensor, with the desired tissue surface. Each electrode's padcontact is measured via the force measurement and/or via a conductionand/or impedance measurement. At step 1406 ablation energy is initiatedto commence ablation of the desired target tissue. Ablation continues atstep 1407 until conduction feedback reaches a predetermined level. Theconduction is measured across the ablation line between an anchorelectrode and an ablator conduction measurement electrode, according toconventional techniques. Once the predetermined level of conduction isreached, the ablation ends at step 1408. Once ablation is complete, theablator is collapsed into its stored position configuration and pulledwithin the outer sheath. The anchor is then collapsed to its storedposition configuration and pulled within its inner sheath. Theillustrative CircumBlator Catheter of the embodiments shown anddescribed is pulled withdrawn out of the pulmonary vein just ablated andmoved into a second pulmonary vein to repeat the process until all fourpulmonary veins are completely ablated.

Q. Operational Embodiment

An operational embodiment employing an umbrella ablator and a mushroomanchor is shown in FIGS. 14-17, showing perspective views of a heart ofa patient undergoing cardiac ablation in accordance with the variousillustrative embodiments described herein, with FIG. 15 depicting theresulting ablations. Referring to FIGS. 14, 16 and 17, the tip of thecatheter 103 with outer sheath 102 reaches the left atrium 1420according to standard techniques, entering the right atrium 1412through, for example, the femoral vein and the inferior vena cava. Thecatheter 103 then penetrates the septum 1414 via a trans-septal puncture1416 between the left and right sides of the heart and enters into theleft atrium 1420. Once inserted into the pulmonary vein 106 d, theanchor 601 is deployed. The anchor expands until a radial wall force isreached, which can be detected by a sensor or other sensing deviceincorporated into the anchor. Although a mushroom anchor 601 andumbrella ablator 402 are shown in these operational embodiments, anyanchoring technique and ablating device as contemplated herein can beemployed. An illustrative force sensor 105, 903 allows measurement ofthe force of the anchor 601 on the pulmonary vein 106 d wall. Thismeasurement step performs two functions, one to minimize chance ofvessel rupture, and the other is to ensure the application of sufficientradial wall force to ensure the anchor remains in place minimizing axialmotion with respect to the pulmonary vein. The anchor should then bepulled distally towards the atrium to seat the anchor both radiallyagainst the wall and axially against the atrial wall-pulmonary veinintersect.

Once the anchor is determined to be in place, the ablator umbrella 402(or point ablator or balloon ablator of other embodiments) expands untilit reaches a predetermined position. The umbrella ablator (or balloonablator described herein) is advanced until it sufficiently compressesagainst the target atrial tissue, as shown in full contact in FIG. 14.The ablation phase occurs by performing an ablation with one or moreelectrodes. If necessary electrode 401 rotating the ablator may berequired to complete a continuous ablation ring. The ablation can beperformed for each pulmonary vein (106 a, 106 b, 106 c, and 106 d), andresults in the depicted ablations 1510, which are shown in FIG. 15.Ideally, the ablations define a predetermined pattern, such as thedepicted ring 1510.

Referring to FIG. 16, the anchor is shown seated within a Pulmonary Vein(PV), and the umbrella ablator remains cinched against the atrialposterior wall. In the ostial area around the same PV, one electrode 401is used as a linear ablator. The electrode 401 that is used to ablatelinear lesions, constructed like a guide catheter with steering wires,is refracted proximally into the outer sheath from the umbrella ablator.The outer sheath 102 is refracted proximally (direction of arrow D10),away from the umbrella ablator and towards the trans-septal puncture1416 to a desired position. The electrode 401 that is used to ablatelinear lesions, constructed as a guide catheter with steering wires, isrefracted proximally into the outer sheath from the umbrella ablator.When the outer sheath 102 is retracted to a desired position (arrow D20)and locked in place, the electrode ablator can then be advanced outbeyond the distal end of the sheath, and steered towards the targettissue. Once the electrode ablator is adjacent to the target, theElectrophysiologist (EP) (or other practitioner) rotates the elongatedpad segment of the electrode so it is oriented in the path of the lineto be ablated. Then the EP illustratively pushes and compresses theelectrode pad against the tissue and ablates (arrow D30). The forcesensor and current/impedance feedback provides information about thelesion creation. Standard mapping techniques are desirable employed tomonitor the ablation position as each location is ablated in turn.

In another embodiment, with the anchor seated within a Pulmonary Vein(PV), the umbrella ablator can be moved/withdrawn proximally, away fromthe PV, and towards the trans-septal puncture. It may or may not bepulled back into its outer sheath. When the umbrella ablator ispositioned in a desired location, between the PV at the distal end andthe trans-septal puncture at the proximal end, one electrode is extendeddistally (arrow D20) and steered towards the target tissue. Once theelectrode ablator is adjacent to the target, the Electrophysiologist(EP) rotates the elongated pad segment of the electrode so it isoriented in the path of the line to be ablated. Then the EP pushes andcompresses the electrode pad against the tissue and ablates (arrow D30).The force sensor and current/impedance feedback provides informationabout the lesion creation.

Once the electrode 401 ablates a first line segment, the electrode 401(and/or the outer sheath 102) is moved parallel with and just beyond oneend of the already ablated line segment. Once properly aligned the nextsegment is ablated, overlapping it with the prior segment. Thisprocedure is repeated until the entire length or segment of the line iscompleted or achieves the desired predetermined pattern and/orelectrical measurement.

Once a Pulmonary Vein is isolated and the neighboring segment of thelinear lesion is completed, the umbrella ablator 402 is withdrawn backinto its outer sheath (such withdrawal can have occurred at a previoustime), the anchor 601 is collapsed and retracted into its inner sheath,the anchor 601 and guide catheter 103 is withdrawn from the PV andinserted into the next PV. The above-described insertion process andsubsequent withdraw is then repeated until the overall medical treatmentis complete.

With reference to FIG. 16, to create a roof line 1610 each half of thisline is generated when the anchor was seated in the right superiorpulmonary vein (RSPV) 106 a and left superior pulmonary vein (LSPV) 106d. In addition to creating the roof line ablations, the ablator canperform other adjacent linear ablations. It should be readily apparentto those having ordinary skill that the ablators as shown and describedherein can perform any linear ablations in the left atrium.

To create the line to the mitral annulus 1430 from the roof line (notshown), the upper portion of the line is made with the anchor seated inone of the upper pulmonary veins and the other portion with the anchorseated in one of the right lower pulmonary vein (RIPV) 106 b and leftlower pulmonary vein (LIPV) 106 c.

One or more electrodes of the umbrella ablator can be steerable, inaccordance with the illustrative embodiments. In an embodiment, if onlyone electrode is steerable, then the catheter can be rotated to properlyposition that electrode with respect to the target location. If there issufficient space, two electrodes can be provided with steerability, andare constructed illustratively in an arrangement in which each electrodeis diametrically opposed within the catheter.

The arrangement of FIG. 16 allows one device, the umbrella ablator, toablate both PVI, and one or more of its electrodes can be employed tocreate a continuous linear ablation with a series of overlapping linesegments. This structure allows the umbrella anchor to be stabilized atthe pulmonary vein, along with the catheter acting as a platform fromwhich the electrodes can be advanced radially away from the catheter tocreate the linear ablations. The catheter platform provides a stablebase from which to ablate and provides stable contact as compared toprior art stand-alone point ablators. This makes the entire procedurereadily reproducible and quicker for EPs to achieve the predeterminedablation pattern.

Another option for performing ablations, although not shown, is toremove the umbrella ablator and insert a standard point ablator. Thiscan be an RF or cryoablator, depending on the preference of the EP. Itis inserted along the guide catheter part way into the left atrium. At adesired position the EP steers the point ablator laterally (radiallyoutward) from the axis of the catheter towards the target tissue. Oncethe target tissue is reached the EP ablates. When complete the EP movesthe point ablator a small distance to overlap the prior ablation point.Notably, the anchored catheter 103 acts as a platform from which thepoint ablator can be maneuvered.

With a point ablator a procedural option is to perform all the PVIablations, and thereby the anchor is inserted into and removed from eachPV, after each PV is isolated. After PVI is complete for all the PVs,the umbrella ablator is removed, then the point ablator is inserted. Theprocess of inserting and removing the anchor into each PV is repeatedfor the point ablator and subsequent creation of the neighboring linearlesions of each PV. A second procedural option is to remove the umbrellaablator after each PV is isolated, then insert the point ablator andperform the linear lesion ablation while the anchor remains seated inthe PV, after which the anchor is removed and then inserted into thenext PV.

In addition, to insure that the catheter is as secure of a platform asappropriate from which to push the single electrode, or point ablatorcatheter against the atrial wall, in order to optimize contact, it isdesirable to maintain the anchor and umbrella ablator in the pulmonaryvein. With those components in place the EP pulls the catheterproximally as tight as possible without disruption to the pulmonary veinin order to keep the catheter sufficiently tight. In case this ifinsufficient, a restraint is needed to stop the catheter from sagginginside the left atrium.

Reference is made to FIG. 17 showing an exemplary restraint as a balloonsupport 1710. In other embodiments, the restraint can be constructed asa group of struts that open similar to restrict distal motion withrespect to the septal wall. The balloon support 1710 or other restraintstructure assists in preventing the catheter 103 from sagging whileperforming ablations and before and/or after the ablations areperformed.

R. System for Performing Cardiac Ablation

Reference is now made to FIG. 18 showing an overview of system 1800employing an anchoring device 601 and an ablator device 402 forperforming cardiac ablations in accordance with any of theimplementations herein. As shown, a mushroom anchor 601 is employed andan umbrella ablator 402 is employed, however any anchoring and ablatingdevices can be employed in accordance with the teachings herein. Acontroller 1810 is operatively connected to the catheter 103 to controlthe ablator 402 and the anchor 601. The anchor 601, ablator 402 andcontroller 1810 are also operatively connected to a system server 1820that controls functionality of the overall system 1800. The systemserver 1820 can be a stand-alone computer (or other processor), acomputing application, a set of software instructions configured tocarry out the functions within the system 1800, or other combinations orsoftware and hardware components in accordance with the teachingsherein. The system server 1820 includes an application 1822 thatincludes all functions and applications of the system. This includesinstructions for performing the various tasks and other functionalitiesof performing the anchoring and ablation as described herein. The systemserver 1820 also includes a power supply 1824 for the componentsthereof. This power supply can be within the system server 1820 asshown, or as a separate component in other embodiments. A RadioFrequency (RF) generator 1826 is also provided to generate theappropriate signals for performing various functions in the diagnosticor therapeutic procedures described herein, including cardiac ablation.Other energy modes and accompanying generators can also be used insteadof RF. There is also included an irrigation pump 1828 as conventionallyprovided during these diagnostic and/or therapeutic procedures. Adisplay 1830 can also be provided, which is operatively connected to thesystem server 1820 for displaying appropriate data and information asdesired.

It should now be apparent that the various anchoring and ablatingcatheters described herein are generally applicable in performingcardiac ablations and similar related procedures. Any of the anchoringdevices can be combined with any ablator devices as described hereinwithout departing from the scope and purpose of the teachings herein.

The foregoing has been a detailed description of illustrativeembodiments of the invention. Various modifications and additions can bemade without departing from the spirit and scope of this invention. Eachof the various embodiments described above may be combined with otherdescribed embodiments in order to provide multiple features.Furthermore, while the foregoing describes a number of separateembodiments of the apparatus and method of the present invention, whathas been described herein is merely illustrative of the application ofthe principles of the present invention. For example, variouscombinations of anchoring devices and/or ablator devices have been shownand are described together. Any combination of anchor and ablatordevices can be employed in accordance with the teachings herein. Inaddition, directional and locational terms such as “top”, “bottom”,“front”, “back”, and “side” should be taken as relative conventionsonly, and are not absolute. By way of example, in further embodiments,the deployment of the umbrella anchor or balloon anchor can utilize anovel catheter that is dedicated to the placement of the anchor in amanner similar to techniques in which practitioners place a conventionalstent. In such embodiment, subsequent t placement of the anchor, thepractitioner is free to insert a commercially available ablator of anyappropriate configuration. Illustratively, a replacement couplingmechanism can be operatively connected to the distal tip of theconventional ablation catheter. This mechanism and features on theanchor can allow the distal tip of the conventional ablator to be guidedinto a latching mechanism. When the illustrative ablations are complete,then the resulting latched catheter can withdraw the anchor for removal.Accordingly, this description is meant to be taken only by way ofexample, and not to otherwise limit the scope of this invention.

1. A catheter for diagnostic or therapeutic procedures comprising: ananchor device on a distal end of the catheter, which when deployed froma stored position contacts a first target tissue to maintain a positionof the catheter relative to the first target tissue; and an ablatordevice proximal to the anchor device, which when deployed from a storedposition, expands and is constructed and arranged to be compressedagainst a second target tissue and thereafter emit an electrical signalto ablate a region of the second target tissue; wherein the ablatordevice is rotatable about an axis of the catheter to perform a pluralityof ablations, thereby resulting in an ablation of a predeterminedconfiguration on the second target tissue.
 2. The catheter as set forthin claim 1 wherein the anchor device is one of: an umbrella anchorhaving a plurality of struts, an umbrella anchor having a plurality ofstents, a mushroom anchor having a plurality of spring struts.
 3. Thecatheter as set forth in claim 1 wherein the anchor device is aballoon-type anchor.
 4. The catheter as set forth in claim 1 wherein theanchor device is guidable into a pulmonary vein to provide an anchor forthe catheter in performing cardiac ablations, and the ablator devicedoes not enter the pulmonary vein when performing the plurality ofablations.
 5. The catheter as set forth in claim 1 wherein thepredetermined configuration comprises one of an ablation ring and alinear ablation line, and wherein the line includes one of a continuousseries of overlapping segmented, curved, and bent line segments.
 6. Thecatheter as set forth in claim 1 wherein the anchor device includes afirst electrical conductor and the ablator device includes a secondelectrical conductor such that a conductance can be measured between thefirst electrical conductor and the second electrical conductor when theanchor device and the ablator device are each in the deployed positions,to determine if the first target tissue has been sufficientlyelectrically isolated from the second target tissue.
 7. The catheter asset forth in claim 1 wherein the anchor device includes a sensor tomeasure contact force against the first target tissue.
 8. The catheteras set forth in claim 1 wherein a contact surface of the first targettissue is treated with a bio-compatible and blood-compatible materialwhich imparts enhanced friction force on the contact surface, to therebyrestrict motion of the anchor device with respect to the second targettissue.
 9. The catheter as set forth in claim 1 wherein the ablatordevice further comprises microspikes for enhancing conduction through acontact surface of the second target tissue.
 10. The catheter as setforth in claim 1 wherein the ablator device further comprises a sensorto measure contact force against the second target tissue.
 11. Thecatheter as set forth in claim 1 wherein the ablator device furthercomprises a blood pressure sensor to measure blood pressure proximal theablator device.
 12. A method for performing cardiac ablation, the methodcomprising the steps of: providing a catheter that includes an anchordevice on a distal end thereof and an ablator device proximal to theanchor device, the anchor device and the ablator device each comprisingan electrical conductor; inserting the anchor device into a pulmonaryvein; expanding the anchor device to contact the pulmonary vein andmaintain a position of the catheter relative to the pulmonary vein;deploying the ablator device from its stored position to its deployedposition, the deployed position having a predetermined size; moving theablator device towards a surface of an atrial wall proximate thepulmonary vein; initiating electrical signal in the ablator device toablate the surface of the atrial wall and ablating the surface of theatrial wall in a predetermined pattern until conduction as measuredbetween an electrical conductor on one side of the ablation line iselectrically isolated from an electrical conductor on the other side ofthe ablation line.
 13. A system for performing cardiac ablationscomprising: a catheter comprising an anchor device and an ablatordevice, the catheter constructed and arranged to perform cardiacablations; a system server operatively connected to the catheter andincluding an application that performs functions related to the cardiacablations to control the anchor device and the ablator device; and acontroller operatively connected to the catheter and the system serverto control functions related to the cardiac ablations.
 14. A method forcreating linear ablations, comprising the steps of: providing a catheterthat includes an anchor device on a distal end thereof and an ablatordevice proximal to the anchor device, the anchor device and the ablatordevice each comprising an electrical conductor; extracting a singleablator electrode from the ablator device; maneuvering the ablatordevice towards a target tissue area; applying a force to the singleablator electrode against the target tissue area; applying energy tocreate an ablation segment; and moving the single ablator electrode toan adjacent location such that a portion of the single ablator electrodeoverlaps the prior ablation segment, wherein energy is applied to thesingle ablator electrode to continue to create ablation segments until acomplete line pattern is formed.